Lyme Disease - Borrelia burgdorferi

They’re back! With spring just around the corner, ticks will be out in abundance and making an effort to find a host! If you own a dog or cat, then you already know about ticks. So, you should also be aware of the diseases that can be transmitted from these eight-legged arachnids to your furry friend. One of the most well known tick borne illnesses is Lyme disease and it is a major concern for dog owners.

Lyme Disease History

Lyme disease (also known as tick fever) is caused by the Borrelia burgdorferi bacterium. Discovered more than 100 years ago, it is fast becoming a major concern for many dogs and their owners. The disease became well known in 1975 - 1976 when a cluster outbreak occurred in the area of Lyme Connecticut, resulting in a number of children developing arthritis. It was first misdiagnosed as juvenile rheumatoid arthritis, until the real culprit was discovered.

Transmission

Lyme bacteria occur naturally in wild animals and are transmitted from animal to animal, through tick bites. They cannot live outside of the host (mammal or a tick). Tiny deer ticks acquire the bacteria when they attach to white footed mice. Once the tick detaches from the mouse, it can reattach to another animal (including people). A deer tick must remain attached for at least 24 – 48 hours in order for transmission of the bacteria to be successful. Deer ticks are commonly found in the Northeast, the upper Mississippi area, California and southern states.

Deer ticks have a 4-stage life cycle (egg, larva, nymph, adult). It is the nymph stage that commonly transmits the disease to dogs and humans, when they attach and bite (drawing a small amount of blood). Depending on the region, anywhere from 10-50% of nymphs harbor the bacteria. Adult deer ticks prefer larger hosts, such as deer, but will also attach to dogs and people. Lyme disease cannot be transmitted between canines and people (ex: a Lyme infected dog or person cannot infect other dogs or people).

Symptoms

Once a canine is infected by Lyme disease, it may take weeks or months for the first symptoms to appear. Many dogs will never develop clinical symptoms but will develop antibodies to the bacteria. Typically, the first symptom is arthritis and a high fever (> 102.5° F). If left untreated, Lyme disease can affect a variety of body systems. Problems can arise in the heart, kidneys and joints and on rare occasion the nervous system. Symptoms range from fever, loss of appetite (anorexia), inflamed lymph nodes, inflamed joints leading to lameness (which sometimes shift from leg to leg), kidney disease, heart disease and neurological disease.

Diagnosis

If your vet suspects your dog may be infected with Lyme, a simple in-house blood test is the first step in diagnosis. Exposed dogs will test positive within 3-5 weeks of infection and will remain positive for more than a year. This is why it is important to test your dog at least once every year.

The Canine Snap 4DX, from Idexx, tests for (4) different canine diseases and only requires a few drops of blood. It will detect exposure to Heartworm (mosquito transmission), Lyme, Ehrlichia and Anaplasmosis (3 tick borne illnesses affecting white blood cells, but also red cells and platelets). It only takes 8 minutes for results to appear, so the test is done while you and your dog are still at the veterinary hospital. If antibodies to Lyme disease are detected, it means the dog has been exposed to the bacteria. Dogs that have been vaccinated against Lyme will not test positive on this blood test. Your veterinarian will base his or her final diagnosis on test results, symptoms and whether the dog responds to treatment.

Treatment

If your veterinarian recommends treatment for your dog’s Lyme disease, it will consist of a course of antibiotics for at least 28 days. The antibiotic of choice is Doxycycline. However, some dogs do not tolerate Doxycycline well and can be treated with Amoxicillin. An animal affected by Lyme disease does not maintain any natural immunity to the disease after exposure and treatment. Thus, they can be re-infected with the disease again and again.

Prognosis

Once antibiotics have been started, symptoms should start to decline within 2-3 days, eventually disappearing altogether. At this point, even though your dog’s symptoms fade and she starts to feel better, it is important to finish the entire course of antibiotics as the disease can recur.

Prevention

Dogs affected by Lyme disease do not maintain any natural immunity to the disease after exposure and treatment. Therefore, they can be re-infected with the disease. So, how can you reduce your dog’s chances of acquiring Lyme disease?

• Avoid exposure to ticks as much as possible.

  On your property, keep bushes, trees and lawns trimmed back, so ticks have fewer areas to cluster in.

  Thoroughly examine your dog at least once a day (twice a day is preferred) and remove any ticks. Deer ticks are very tiny, and are not easily detected when they first climb on your dog. The tick then bites the dog and must be attached for 24 - 48 hours in order to transfer the bacteria. This is the point where many owners discover the tick, which is starting to increase in size and feels like a small lump on your dog’s skin.

• The easiest and quickest way to remove a tick is to part the dog’s hair, grasp the tick around the body and then use firm, steady pressure to extract it from the dog. You may want to use a small piece of tissue paper, to provide a firmer grip around the tick’s body as you withdraw it. Tweezers may also be helpful in grasping the tick.

  Avoid using any solutions or ointments on the tick, to ‘smother’ and kill it. Remember ticks are very tough. These remedies are not helpful, as they may irritate, burn or injury your dog’s skin in the process of removing the tick.

  Tick remover tools sell for about $5-10 and can be found at most pet stores.

• Use a topical tick preventative such as Frontline or Advantix on your dog.

  While these products do not prevent ticks from getting onto your dog, they will work to kill the tick, or cause it to drop off within
  24 - 48 hours and reduce the chance of bacterial transmission.

• A Lyme vaccine will help prevent infection.

  Since no vaccine is 100% effective in preventing disease there are pros and cons to this issue. As always, discuss vaccine options with your veterinarian to determine the best course of action for your dog.

  • Evidence against vaccinating includes: 90% of infected dogs will never become ill. The small percentage of exposed dogs (5-10%) that will become ill can easily be treated with safe, inexpensive antibiotics.
  • Evidence in favor of vaccinating includes: preventing the illness in areas where Lyme disease is prevalent. Vaccination may also reduce the occurrence of the kidney disease side effect of Lyme.

• Tick season varies in each region and they are hardy and can thrive even in harsh conditions. In New England, ticks are out for 8 – 9 months of the year. Ticks are more active in the spring and fall and less active in the hot summer months. A good rule of thumb is if there is a solid snow cover on the ground, you and your dog are probably safe. Otherwise, as soon as the snow starts to melt, ticks start to re-emerge.

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